Neuromuscular junction dysfunction in Miller Fisher syndrome.

The Miller Fisher syndrome (MFS) is a variant of Guillain-Barre syndrome with the clinical triad of areflexia, ataxia, and ophthalmoparesis. The classic pathologic mechanism of disease is considered to be peripheral nerve demyelination. We present a patient with binocular diplopia and a diagnosis of myasthenia gravis from 15 years prior. Electrophysiologic studies revealed a decremental response on repetitive nerve stimulation, suggesting recurrent myasthenia. However, pupillary light-near dissociation and areflexia were present and positive anti-GQ1b antibodies confirmed MFS. This patient highlights a developing recognition of impaired neuromuscular transmission in MFS. His presentation is discussed in the context of the animal and human literature on neuromuscular junction abnormalities in MFS.

Hypoglycemic hemiplegia: insulinoma masquerading as stroke.

We report a patient with recurrent episodes of hemiplegia caused by hypoglycemia. Investigations revealed an insulinoma, which was surgically removed. After this, the blood glucose level normalized and the patient remained asymptomatic for 9 months. We discuss pathophysiological mechanisms whereby hypoglycemia might cause focal neurological deficit.

Juvenile progressive bulbar palsy. Clinical and electrodiagnostic findings.

Differentiation of juvenile progressive bulbar palsy from bulbar myasthenia gravis is difficult. Characteristics of both may include ocular involvement, fluctuant course, abnormal fatigability, and normal acetylcholine receptor (AChR) antibody titers. Electrodiagnostic evaluation may demonstrate moment-to-moment variability in motor unit action potential amplitude, fibrillation potentials, and decremental motor evoked responses. Increased jitter with blocking may be the most prominent electrodiagnostic abnormality in either disorder, even in asymptomatic extremity muscles. Complete paralysis of facial muscles with electrical silence on needle electromyography, low-amplitude facial evoked responses without a decrement to repetitive stimulation, increased jitter and fiber density in asymptomatic extremity muscles, and normal AChR antibody levels suggested juvenile progressive bulbar palsy in two patients initially thought to have bulbar myasthenia. Early differentiation of these disorders is important because of therapeutic, genetic, and prognostic implications.